Bispiperazido phosphorus acid esters

ABSTRACT

Compounds useful as lube oil additives are prepared by reaction of phosphorus halides and piperazine derivatives.

This is a continuation of application Ser. No. 628,288, filed Nov. 3,1975, now U.S. Pat. No. 4,081,445.

FIELD OF THE INVENTION

This invention concerns bis-piperazido phosphorus and trispiperazidophosphorus compounds, and methods for the preparation of thesecompounds.

Various of the compounds obtained according to the invention are ofinterest as components of petroleum compositions, as additives forplastics materials, as components of flame-resistant or flame-retardantpolymers, as pharmaceuticals or as intermediates in the production ofpharmaceuticals.

BACKGROUND OF THE INVENTION

It is known that halides of phosphorus are able to react with primaryand secondary amines, thereby producing amides of the various acids ofphosphorus. For instance, as long ago as 1898, Michaelis and Kaehner inBer., 31 (1898), pp 1040-1047 described the reaction of piperidine andtetrahydroquinoline with phenyl phosphorous dichloride to form thecorresponding bis-piperidide and bis-tetrahydroquinolide. Thesecompounds could be converted into the corresponding amides of phosphonicand phosphonothionic acid.

Subsequent work has described the reaction of phosphorus halides oroxyhalides with a variety of amines, and hydrazine. Attention is to bedirected in this connection, for instance, to U.S. Pat. Nos. 2,906,770;3,107,231; 3,260,702 and 3,649,594. Little attention, however, has beenpaid to the use of piperazine or substituted piperazines as aminereactants.

A paper by Bello et al in Macromolecules, 3 (1970) pp 98-100 describesthe reaction of dimethylphosphoramidic dichloride (CH₃)₂ --N--POCl₂ withan excess of piperazine to give phosphoric dimethylamido bispiperazide.##STR1##

This compound was subsequently reacted with oxalyl dichloride orpiperzine--1,4--dicarbonyl chloride to give polymers. Polymers withalternating piperazine and (CH₃)₂ N--PO: groups were obtained by usingan excess of the phosphorus halide.

The object of the present invention is the preparation of novelphosphorus compounds containing piperazine rings. Other objects of theinvention are to produce novel phosphorus compounds useful as componentsof petroleum compositions. Further objects will be apparent to thoseskilled in the art.

STATEMENT OF THE INVENTION

The present invention provides compounds of the formula: ##STR2## andsalts of such compounds, wherein X represents an oxygen or sulphur atomor is absent, Y represents an (i) aliphatic, cycloaliphatic, or aromatichydrocarbon group or a heterocyclic group; (ii) a group of the formula--NR₂ in which each group R represents a hydrogen atom, an aliphatic,cycloaliphatic, or aromatic hydrocarbon group or a heterocyclic group,or the two groups R, together with the nitrogen atom to which they areattached, represent a N-containing heterocyclic ring; (iii) a group ofthe formula --OR in which R has the meaning given above; or (iv) a groupof the formula: ##STR3## R¹ represents a substituent on the piperazinering; R² represents a hydrogen atom or a substituted or unsubstitutedaliphatic, cycloaliphatic or heterocyclic radical or heterocyclic group,an acyl group, a sulphonyl group a substituted phosphonyl group or asubstituted carbamoyl group; and

n represents 0 or an integer, and salts of such compounds in which atleast one of the groups R² represents a hydrogen atom;

but with the proviso that Y does not represent dimethylamino when Xrepresents oxygen and R¹ and R² both represent hydrogen.

DESCRIPTION OF THE INVENTION

In the present invention the symbol X can represent an oxygen or sulphuratom, or it can be absent. The compounds according to the invention aretherefore amides of phosphoric acid (when X represents oxygen),thiophosphoric acid (when X represents sulphur), and phosphorous acid(when X is absent).

The symbol Y can represent a group of the formula: ##STR4## in whichcase, the compounds of the invention are trispiperazides. When Y has oneof its other meanings, the compounds are bispiperazides.

Y can for example represent a substituted or unsubstituted hydrocarbongroup, which can be of aliphatic, cycloaliphatic or aromatic nature.Examples of suitable aliphatic groups are alkyl, such as methyl, ethyl,propyl, butyl, octyl, dodecyl, or octadecyl; alkenyl, such as allyl; oralkynyl, such as propargyl.

Examples of suitable cycloaliphatic groups are cycloalkyl, such ascyclohexyl, tetrahydronaphthyl or decahydronaphthyl; and cycloalkenyl,such as cyclohexenyl.

Examples of suitable aromatic hydrocarbon groups are aryl groups, suchas phenyl, naphthyl, biphenyl, or phenanthryl; aralkyl, such as benzyl,or phenylethyl; and alkaryl, such as tolyl, dimethylphenyl,trimethylphenyl, cumyl, or p-octylphenyl.

Y can alternatively represent a heterocyclic group, linked to thephosphorus atom through a carbon atom, as in the tetrahydrofurfuryl or2-pyridyl radicals.

Y can also represent a group of the formula --NR₂, in which each Rrepresents a hydrogen atom, or an aliphatic, cycloaliphatic, or aromatichydrocarbon group or a heterocyclic group. Examples of these hydrocarbongroups or heterocyclic groups are given above. Specific examples ofsuitable amino radicals are dimethylamino, diethylamino, dipropylamino,dibutyl amino, monomethyl amino, monoethylamino, monododecyl amino,mono-(C₁₀₋₁₄) alkylamino, monooctadecylamino, anilino, p-dodecylanilino,and N-butylanilino.

Alternatively, both symbols R, and the nitrogen atom to which they areattached, can together represent a heterocyclic radical linked to thephosphorus atom through the nitrogen atom. Examples of such groups aremorpholino, piperidino, tetrahydroquinolino, pyrrolidino etc. Thecompounds in which Y represents a further piperazino group are, ofcourse, a special instance of this.

Y can also represent a group of the formula --OR in which R has themeaning given above. Examples of such groups are alkoxy, such asmethoxy, ethoxy, propoxy, butoxy, dodecyloxy and octadecyloxy; andaryloxy such as phenoxy, tolyloxy, or benzyloxy.

Any of the above radicals can if desired, be substituted. The onlylimitation upon the nature of the substituents is that they should beinert under the conditions of the reaction employed in synthesizing thecompound.

In the group of the formula: ##STR5## R¹ represents a substituent on thepiperazine ring. Here again, the only limitation upon the nature of thesubstituent is that it should be inert under the conditions of thereaction used to synthesize the compound. The substituent can, forexample, be one of the groups set out above for Y, provided that such agroup is inert. When present, it can for example be an alkyl group, suchas a methyl group. Alternatively, the substituent can have a meaning notset out above, insofar as it might not be an appropriate group forattachment to phosphorus: for example, an oxo group. Specific examplesof substituted piperazine groups are 2,5-dimethylpiperazino and2,5-dioxopiperazino groups, n is 0 or an integer, and is preferably 0, 1or 2: R² can represent a hydrogen atom or a substituted or unsubstitutedaliphatic, cycloaliphatic or aromatic hydrocarbon group or aheterocyclic group. Examples of suitable groups are set out above.Specifically preferred groups R² include alkyl, such as methyl, ethyl,phenyl, and substituted groups such as β-cyanoethyl and β-carbethoxy- R²can also represent an acyl group, e.g. of an aliphatic, cycloaliphatic,aromatic or heterocyclic carboxylic acid, such as acetic, propionic,butyric or stearic acid, cyclohexane carboxylic acid, benzoic acid,toluic acid, nicotinic acid or a methylnicotinic acid. Alternatively R²can represent a sulphonyl group, for example a methane sulphonyl,benzene sulphonyl or toluene sulphonyl group.

R² can also represent a substituted phosphorus-containing group, e.g. agroup of the formula

    --PX R.sub.2.sup.3

in which X has the meaning given above, and

R³ represents an aliphatic, cycloaliphatic or aromatic group, or a groupof the formula --OR, --SR or NR₂ in which R has the meaning given above.An example of such a group is dimethylaminophosphonyl.

R² can also represent a substituted carbamoyl group --CO--NHR wherein Rhas the meaning given above. An example of such a group isphenylcarbamoyl.

The invention also provides lubricating compositions comprising a majoramount of a lubricating oil, and a minor amount (e.g. 0.1 to 10% byweight, preferably 0.5 to 2.5% by weight) of a piperazidophosphoruscompound as defined above. The invention further provides a concentratesuitable for incorporating in a lubricating oil comprising apiperazidophosphorus compound as defined above and an inert diluent. Theproportions of the diluent are not critical and the weight ratio ofpiperazidophosphorus compound to diluent may, for instance, range from9:1 to 1:9 depending on miscibility.

Preferred lubricating compositions and concentrates comprisep-(p'-dodecylanilino) phenyl bispiperazido thiophosphate, andp-(p'ethylanilino) phenyl bis-(N'-β-carbethoxyethylpiperazido)thiophosphate.

This invention also provides methods for the synthesis of the compoundsdescribed above. According to a preferred method, a compound of theformula: ##STR6## wherein y is an integer 0-1 (When y is 0, the compoundhas the formula iv; when y is 1, the compound has the formula v:##STR7## in which X and Y have the meanings given above and Halrepresents chlorine or bromine) is reacted with an excess of apiperazine derivative of the formula: ##STR8## in which R¹, R² and nhave the meanings given above.

Compounds of the formula X═P(Hal)₃ and ##STR9## are well known in theart. Some of them will be commercially available, and others may beprepared by the methods described in, for example Houben-Weyl "Methodender Organischen Chemie" Vol XII/2, or by Olah and Oswald in Ann. 625(1959) 92-94.

Similarly, the piperazine derivatives will be well known in the art, andthe preferred compound, piperazine itself, is commercially available. Itis of course possible to employ a mixture of piperazine derivatives,thereby giving compounds in which the groups R¹ and/or R² on differentpiperazine rings are themselves different.

According to one preferred embodiment, the reaction according to theinvention can be carried out by adding the phosphorus halide, as such ordissolved in an inert solvent, to a large excess of the piperazine,generally in a molar ratio of at least 1:4, either as such or dissolvedin an inert solvent. Suitable solvents include, benzene, otherhydrocarbons, ether or chloroform. The piperazine will act as both acatalyst and a halogen acid-acceptor.

The reaction is exothermic and can be moderated by controlling the rateat which the phosphorus halide is added. The reaction can generally becarried out at room temperature, but is is possible to carry it out atelevated temperature, e.g. at a temperature of 60° to 80° C. in benzene,toluene or xylene or at the reflux temperature of the solvent employed.Most conveniently the reaction is carried out at atmospheric pressure,but superatmospheric pressures can be employed if desired. Thepiperazine hydrohalide that forms is insoluble in many solvents, e.g.ether, benzene, and other hydrocarbons, and can be separated byfiltration. It can also be removed by washing with water or an aqueoussolution of sodium carbonate. Subsequently, any solvent and any excessof the piperazine can be distilled off, and the resulting crude productcan be purified by recrystallization, low-pressure distillation or achromatographic technique.

Alternatively, the reaction can be carried out in the presence of atertiary amine as catalyst and hydrogen halide-acceptor. Examples ofsuitable tertiary amines are triethylamine, pyridine, dimethylanilineand lutidine. The tertiary amine can be present in either or both of thephosphorus halide and the piperazine. It is most convenient however touse piperazine as catalyst and hydrogen halide-acceptor as the reactioncourse is more easily followed.

At least stoichiometric amounts of piperazine, corresponding to thephosphorus halide, are required in this embodiment of the invention, andadvantageously an excess of the piperazine is employed. The molar ratioof phosphorus halide: piperazine: tertiary amine, can be, for example1:2:2.

When R² in the piperazine reactant is hydrogen, for instance inpiperazine itself, the product of the synthetic reaction will have thestructure: ##STR10## and will itself be capable of undergoing furtherreactions. For instance, the N--H group can be subjected to asubstitution reaction with a compound of the formula R² --Hal, forinstance an acyl, phosphonyl or sulphonyl halide such as acetylchloride, benzoyl chloride, phenyl dimethylaminophosphonyl chloride,benzene sulphonyl chloride or toluene sulphonyl chloride.

Alternatively the compound of formula VII can be reacted with an acryliccompound of the formula:

    CH.sub.2 ═CH--Z                                        VIII

wherein Z represents a cyano, carboalkoxy, sulphone (SO₂ R) orphosphonyl (PX R₂) group, e.g. with acrylonitrile or an ester of acrylicacid. The products have the formula II in which R² represents a group ofthe formula --CH₂ --CH₂ --Z.

Yet another reaction which can be undergone by compounds of the formulaVII is reaction with an isocyanate of the formula R--NCO wherein R hasthe meaning given above. The products of this reaction are substitutedureas of the formula II in which R² represents a group of the formula:

    --CO--NH--R                                                IX

Examples of suitable isocyanates are methylisocyanate and phenylisocyanate.

The compounds according to the invention have a variety of uses. Theyconstitute multifunctional lubricating oil additives, exhibiting ananti-corrosion-oxidation action and an anti-wear action, and are mildextreme pressure agents. Since the compounds in which R² representshydrogen are difunctional and trifunctional secondary amines, they areable to participate in polymer-forming and cross-linking by polyadditionand polycondensation reactions. The compounds in which R² for examplerepresents a β-carboalkoxyethyl group constitute flame-retardantplasticizers. Other actual and potential uses will be apparent to thoseskilled in the art.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Practice of this invention will be apparent to those skilled in the artfrom inspection of the following illustrative examples.

EXAMPLE 1

0.20 mole of phenyldichlorophosphate dissolved in 50 ml of benzene wasadded dropwise to a mixture of 4.0 mole of piperazine and 0.50 mole oftriethylamine dissolved in 800 ml of benzene at 50°-80° C. The mixturewas mechanically stirred. When all the acid chloride was added, themixture was refluxed for one to two hours and the precipitatedtriethylamine hydrochloride was filtered off. The filtrate was cooled,and more precipitated hydrochloride was filtered off. The solvent andthe excess of piperazine were distilled off at normal pressure. 250 g.of piperazine were recovered. The remaining piperazine was removed undervacuum at 60°-90° C. and a crude product was obtained, which could becrystallized from benzene from acetone or from a mixture of both,yielding colourless white crystals of phenylbispiperazidophosphate mp,114.5°-115° C. The crude product can also be purified by vacuumdistillation b.p. 235°/0.4 mm. The total yield was more than 60% of thetheoretical amount.

A standard procedure used for the synthesis of bispiperazido compoundsis as follows:

To 1 mole of anhydrous piperazine dissolved in 600 ml of dry benzene at50°-80° C. is slowly added 0.10 mole of the phosphorus acid dichloride(Y--PXCl₂ ; X═O,S or absent) dissolved in 50 to 100 ml of benzene, whilethe mixture is gently stirred. The mixture is then refluxed for 15 to 30minutes and the precipitated piperazine hydrochloride is filtered off.Benzene and the excess of piperazine are distilled off at reducedpressure (up to 80°-100° C. at 1 mm). This process easily occurs on athin film rotating evaporator. The residue is redissolved in benzene(400 ml) and the remaining piperazine hydrochloride is filtered off.Benzene and the remaining piperazine are then distilled off under vacuum(up to 100° C. at 0.5-1 mm) which yields the crude piperazidophosphoruscompound.

Sometimes toluene or xylene was used as a solvent to provide a higherreaction temperature, needed to complete the reaction (e.g. forbispiperazidophosphoric triamides), which also had the advantage that itprevented blocking of the condensor by sublimed piperazine when it wasdistilled off. Purification of the crude products was sometimes possibleby recrystallization or by distillation, but most compounds decomposedupon distillation; several were viscous oils which sometimes solidifiedon standing.

For this preparation usually piperazine itself was used as HCl-acceptorbecause the use of other bases e.g. triethylamine gave no advantages. Incontrast, using triethylamine, it was not possible to determine theextent of conversion on the basis of the amount of salt formed, becausea mixture of triethylamine hydrochloride and piperazine hydrochlorideprecipitated during the reaction.

A variant of the work-up method consists in washing out the piperazinehydrochloride and piperazine from the reaction mixture with water ordilute sodium carbonate solution, directly after the reaction orpreferably after the removal of the main part of piperazine and/or itssalt. This procedure is not suitable for piperazidophosphorus compoundswhich have good solubility in water, and hence it is recommended toextract such phosphorus compounds from the wash waters, for example withchloroform, to avoid extensive losses of the reaction product.

Typical examples of compounds prepared by the standard procedure are:

EXAMPLE 2

Phenyl bispiperazidophosphate ##STR11##

0.5 mole (105.5 g) of C₆ H₅ --O--POCl₂ was reacted with 5 mole (430 g)of piperazine dissolved in 3 l of benzene. The standard work upprocedure, including filtration of the hydrochloride and distillation ofthe solvent and excess piperazine, yielded 143 g (92%) of a crudeproduct which was first recrystallized from benzene (yield: 115.5 g;74.3%) and then from benzene: acetone (1:1) which yielded 92.2 g (59.9%)with mp 117°-118° C. From the remaining viscous oil another fraction ofpure compound could be isolated by vacuum distillation (bp 235° C./0.4mm). Other compounds, indicated in Table 1 below, were prepared bysimilar methods.

                  TABLE 1                                                         ______________________________________                                        Bispiperazidophosphoryl Compounds                                              ##STR12##                                                                                   Yield       Melting Point                                      Compound Y =   %           (°C.)                                       ______________________________________                                        OC.sub.2 H.sub.5                                                                             100         oil                                                O(CH.sub.2).sub.17CH.sub.3                                                                   86.4        66.5-68.5                                          OC.sub.6 H.sub.5                                                                             74.3        117-118                                            NH(CH.sub.2).sub.17CH.sub.3                                                                  95          46-47                                              NH[C.sub.10 -C.sub.14 ]                                                                      82.7        oil                                                N(C.sub.3 H.sub.7).sub.2                                                                     100         oil                                                 ##STR13##     82          125                                                NHC.sub.6 H.sub.5                                                                            56          155-157                                            NHC.sub.6 H.sub.4 C.sub.12 H.sub.25                                                          88.8        glossy solid                                       ______________________________________                                    

EXAMPLE 3

Ethyl bispiperazidothiophosphate: ##STR14##

(a) 0.1 mole (17.9 g) of ethyl thiophosphoryl dichloride (C₂ H₅O--PSCl₂) was reacted with 1 mole (86 g) of piperazine dissolved in 600ml of benzene at 70° C. Standard work up (with a maximum temperature of70° C.) yielded a crude yellow oil (27.45 g; 98.5%, mp 84°-95° C.) whichsolidified on standing and which was recrystallized from ether: acetone(4:1) yielding yellow-white crystals with mp 96°-101° C.

(b) 0.0625 mole (11.2 g) of ethyl thiophosphoryl dichloride was reactedat 40° C. with 0.45 mole (39.4 g) of piperazine dissolved in benzene.After removal of the salt, benzene solution was extracted four timeswith water. The benzene solution was dried and concentrated (T<40° C.)yielding an oil F₁ (2.2 g; 12.6%).

The collected wash water was extracted three times with chloroform whichyielded, after evaporation of the solvent, an oil F₂ (13.7 g; 78.7%; mp78.5°81.5° C.) which crystallized out on standing. Overall yield: 15.9 g(91.4%). Elemental analysis of F₂ was correct. Other compounds,indicated in Table 2 below, were prepared by similar methods.

                  TABLE 2                                                         ______________________________________                                        Bispiperazidothiophosphoryl Compounds                                          ##STR15##                                                                                       Yield   Appearance                                         Compound Y =       %       (Melting range °C.).sup.(b)                 ______________________________________                                        OCH.sub.2CH.sub.3  91.4    Yellow oil                                                                    (78.5-81.5)                                        OC.sub.6 H.sub.5   96      Yellow oil                                                                    (56-63)                                            OC.sub.6 H.sub.4NHC.sub.6 H.sub.4C.sub.2 H.sub.5                                                 94      Red Oil                                            OC.sub.6 H.sub.4NHC.sub.6 H.sub.4C.sub.12 H.sub.25                                               98.5    Brown Oil                                          N(CH.sub.2CH.sub.2CH.sub.2CH.sub.3).sub.2                                                        53.7    Yellow oil                                                                    (85-92)                                            N(C.sub.6 H.sub.5)(C.sub.4 H.sub.9)                                                              88.6    Brown oil                                          O(CH.sub.2).sub.17CH.sub.3.sup.(a)                                                               93.2    Waxy solid                                                                    (45-50)                                            ______________________________________                                         .sup.(a) No good elemental analysis was obtained of this compound             -.sup.(b) Melting range of the solidified oil                            

EXAMPLE 4

Phosphorous Di-n-butylamido bispiperazide ##STR16##

To 0.93 mole (80.10 g) of piperazine dissolved in 1.5 l of benzene at45° C. was added slowly 0.07 mole (16.1 g) of Bu₂ NPCl₂ in 100 ml ofbenzene. Then the mixture was warmed up till reflux, filtered, andbenzene and the excess of piperazine were removed under reduced pressure(T_(max) : 100° C.). The crude product obtained was redissolved inbenzene, filtered again and the mixture was concentrated, which yielded19.4 g (84.12%) of the bispiperazidophosphorous compound.

Table 3 below indicates this compound, and the corresponding phenoxycompound, prepared in similar manner.

                  TABLE 3                                                         ______________________________________                                        Bispiperazidophosphorous (P.sup.III) Compounds                                 ##STR17##                                                                    Compound        Yield                                                         Y =             %       Appearance                                            ______________________________________                                        C.sub.6 H.sub.5O                                                                              82.3    viscous oil                                           (C.sub.4 H.sub.9).sub.2 N                                                                     84.1    viscous oil                                           ______________________________________                                    

EXAMPLE 5

Phenyl bis(N'-β-cyanoethylpiperazido)phosphate ##STR18##

0.025 mole (7.75 g) of phenyl bispiperazidophosphate was refluxed with0.075 mole of (5 ml) acrylonitrile in 50 ml of toluene (6-7 hrs). Afterstripping off the solvent and the excess acrylonitrile, a crude oil wasobtained (10.2 g; 97.8%). Purification by vacuum distillation resultedin decomposition of the product (250° C./0.6 mm), which however can bepurified by column chromatography on silica gel (eluting with methanol)yielding a yellow-red viscous oil.

EXAMPLE 6

p-(p'-ethylanilino)phenyl-bis(N'carbethoxyethylpiperazido)thiophosphate.##STR19##

A solution of 6.7 g (0.015 mole) of p-(p'-ethylanilino)phenyl-bis-piperazido thiophosphate and 5 g (0.05 mole) of ethylacrylate in 100 ml of toluene was refluxed for 4-6 hrs. Then toluene andthe excess ethyl acrylate were stripped off under vacuum (temp. max.100° C.) which yielded the title compound, a viscous brown oil, in 96%yield (9.3 g).

EXAMPLE 7

Phosphorous dibutylamido bis-(N'-carbanilidopiperazide) ##STR20##

To 0.005 mole (1.647 g) of phosphorousdibutylamido bispiperazide in 30ml of benzene at 20° C. was slowly added 0.010 mole (1.19 g) of phenylisocyanate in 20 ml of benzene. Immediately a white precipitate wasformed which could be partly recrystallized from boiling ethanol. Yieldof the title compound: 1.8 g; 63.5%, mp 320° C.

EXAMPLE 8

Phosphoric trispiperazide

To 1 mole (86 g) of anhydrous piperazine dissolved in 600 ml of drybenzene at 50°-60° C. was added dropwise with gentle stirring 0.05 mole(7.66 g) of POCl₃ dissolved in 50 ml of dry benzene. The mixture wasrefluxed for 2 hrs at 80° C. and then filtered hot to removeprecipitated piperazine hydrochloride. Benzene and the excess ofpiperazine were distilled off at reduced pressure (up to 80°-100° C. at1 mm). The residue was redissolved in dry benzene, filtered to removeremaining salt, and again benzene and piperazine were distilled offunder reduced pressure.

A crude product was obtained in a yield of 13.7 g (90.7%), melting point130° C. Once it had absorbed water, the compound could not beredissolved and recrystallized from benzene and it became very sticky.Pure product could be obtained again from it, by dissolving it inalcohol (ethanol) and distilling off all the solvents under vacuum(80°-100° C./1 mm). A pale yellowish oil was obtained which crystallizedout upon cooling and standing, and which gave a good elemental analysis.Yield 9 g (59.6%).

EXAMPLE 9

Thiophosphoric trispiperazide

To 1 mole (86 g) of anhydrous piperazine dissolved in 200 ml of tolueneat 100° C. was added dropwise with gentle stirring 0.05 mole (8.47 g) ofPSCl₃ in 30 ml of toluene. The mixture was refluxed for 21 hrs and theprecipitated piperazine hydrochloride was filtered off. Toluene and theexcess of piperazine were distilled off at reduced pressure (100° C./1mm).

15 g of a crude solid were obtained and recrystallized fromtoluene/benzene yielding pale yellow crystals 13.1 g (86.7%) mp129.5°-130.5° C. and which gave a good analysis. This compound wasfairly hygroscopic, and had good solubility in water and alcohol, but itwas not soluble in base oils.

EXAMPLE 10

Thiophosphoric tris-(N'-β-cyanoethylpiperazide)

A solution of 0.02 mole (6.37 g) of phosphorothioic trispiperazide and0.09 mole (4.77 g) of acrylonitrile in 110 ml benzene was refluxed for 6hrs. Stripping off the solvent and excess acrylonitrile (temp max 100°C./10 mm) yielded a crude yellow oil 9.5 g (99%) which was purified bycolumn chromatography over silica gel using methanol as eluent. Purewhite crystals of thiophosphoric tris-(N'-β-cyanoethylpiperazide) wereobtained (7.83 g; 82%; mp 122° C.). The solubility in base oils of thiscompound was very low.

EXAMPLE 11

Thiophosphoric tris-(N'-β-carbethoxyethylpiperazide)

(a) A mixture of 0.010 mole (3.18 g) phosphorothioic trispiperazide and0.030 mole (3.0 g) of ethyl acrylate was heated under reflux for 5 hrsat 140° C. After the excess of ethyl acrylate was distilled off, a brownoil was obtained in 99.5% yield (6.15 g) which gave a good analysis.

(b) A mixture of 0.0104 mole (3.30 g) of phosphorothioic trispiperazideand 0.20 mole (20 g) of ethyl acrylate in 100 ml toluene was refluxedfor 4 hrs. The solvent and excess ethyl acrylate was stripped off whichyielded the compound in 96.6% (6.2 g) yield.

EXAMPLE 12

Only the piperazidophosphorus compounds and derivatives which had asolubility in base oils (SNO-20; 145-PPT) of at least 0.5% wt wereevaluated as lube oil additives. The results are listed in Tables 4, 5,6 and 7 below, and indicate that the bispiperazidophosphoryl compoundsshow a moderate wear protection and mild extreme pressure propertiescompared to ZDT, (a zinc dialkyl dithiophosphate), and cause no coppercorrosion and slight to moderate rusting.

The general performance of the thiophosphoryl compounds was better thanof the phosphoryl compounds. Compared to ZDT, their wear protectingaction is good to excellent, the best results being obtained withcompounds in which X=S and Y=O-alkyl groups and with compounds in whichX=S and in which R² =carboxylic ester (--CH₂ --CH₂ --COOR). All thesecompounds show mild extreme pressure activity and thediarylaminophosphorus compounds (Y=--O--C₆ H₄ --NH--C₆ H₄ --R) areexcellent oxidation inhibitors, superior to ZDT.

Bench test results of the trivalent phosphorus compound, phenylbispiperazidophosphite showed moderate anti-wear and anti-oxidationaction and mild extreme pressure properties.

According to the test results the most promising compounds prepared arep-(p'-dodecylanilino)phenyl bispiperazidothiophosphate ##STR21## andderivatives of the arylaminophenylbispiperazidothiophosphates ##STR22##which give a very good wear protection, an excellent oxidationinhibition and mild extreme pressure activity.

The hydrocarbon base oils designated SNO-20 and 145-PPT have thefollowing properties:

    ______________________________________                                                    SNO-20     145-PPT                                                ______________________________________                                        Sp Gr 60/60F  0.871-887    0.880-876                                          Gravity API   28-31        30-33                                              Vis. SUS at 100° F.                                                                  325-350      140-150                                            Vis, SUS at 210° F.                                                                  53-55        --                                                 VI            90 min.      95 min.                                            Pour Point °F.                                                                       10           10                                                 ______________________________________                                    

                                      TABLE 4                                     __________________________________________________________________________    Evaluation of Bispiperazidophosphoryl Compounds                                                                  4 Ball Mean Hertz    Rotary Bomb                            Blend  Cu-Strip   Navy Wear.sup.3                                                                      Load.sup.4                                                                           Weld Point.sup.4                                                                     Oxidation.sup.5       Compound         wt % in                                                                              corrosion.sup.1                                                                     Rust.sup.2                                                                         micr/min                                                                             kg     kg     min                   __________________________________________________________________________     ##STR23##       1.0 SNO-20 DTA                                                                       1A    slight                                                                             4.6    53.3   158    20                     ##STR24##       0.75 SNO-20 DTA                                                                      1A    moderate                                                                           4.1    53.9   158    40                    ZDT              0.5               --     48     224    --                                     SNO-20 DTA                                                                    1.0    1A    moderate                                                                           0.3    54.9   200    65                                     SNO-20 DTA                                                   SNO-20 DTA       --     1A    severe                                                                             7.3    24     126    40                    __________________________________________________________________________     .sup.1 ASTM-D130, 3hr, 212° F.                                         .sup.2 ASTM-D665A, 60° C., 24 hr                                       .sup.3 ASTM-D 226664, 1800 rpm. 28 kg. room temp.                             .sup.4 ASTM-D 2596, 1500 rpm. room temp.                                      .sup.5 ASTM-2272, 100 rpm. 90 psi, 150° C.                        

                                      TABLE 5                                     __________________________________________________________________________    Evaluation of Piperazidothiophosphoryl Compounds                                                                           Mean                                                 Blend             4 Ball Hertz      Rotary Bomb                               wt %in Cu-strip   Navy-Wear.sup.3                                                                      Load.sup.4                                                                        Weld Point.sup.4                                                                     Oxidation.sup.5                           Base Oil                                                                             corrosion.sup.1                                                                     Rust.sup.2                                                                         micr/min                                                                             kg  kg     min                   __________________________________________________________________________    Compound                                                                       ##STR25##                                                                    Y = OC.sub.2 H.sub.5                                                                              1.0    1A    pass 1.9    54.6                                                                              158    20                                        SNO-20 DTA                                                O(CH.sub.2).sub.17CH.sub.3.sup.a                                                                  1.0    1A    slight                                                                             0.5    43.2                                                                              158    35                                        SNO-20 DTA                                                OC.sub.6 H.sub.5    1.0    1A    pass 2.4    53.2                                                                              158    40                                        SNO-20 DTA                                                                    2.0    1B    pass 2.6    43.2                                                                              158    30                                        145-PPT                                                   N(C.sub.6 H.sub.5)(C.sub.4 H.sub.9)                                                               1.0    1A    pass 1.4    54.2                                                                              158    108                                       SNO-20 DTA                                                OC.sub.6 H.sub.4NHC.sub.6 H.sub.4C.sub.12 H.sub.25                                                0.47   1B    very 1.1    29.1                                                                              158    508                                       SNO-20-DTA   slight                                       Compound                                                                       ##STR26##                                                                    Y = OC.sub.6 H.sub.4NHC.sub.6 H.sub.4C.sub.2 H.sub.5                                              0.5    1A    no rust,                                                                           0.3    29  158    220                                       SNO-20 DTA   deposit                                       ##STR27##          0.6 SNO-20-DTA                                                                       1A    severe                                                                             0.5    43.3                                                                              158    30                    References                                                                    ZDT                 0.5                      48  224                                              SNO-20 DTA                                                                    1.0    1A    moderate                                                                           0.3    54.9                                                                              200    65                                        SNO-20 DTA                                                                    2.0    1A    severe                                                                             2.6    67.4                                                                              200    210                                       145 PPT                                                   SNO-20 DTA          --     1A    severe                                                                             7.3    24  126    40                    145 PPT             --                6.6    23  126    20                    __________________________________________________________________________     .sup.1 ASTM-D130, 3 hr. 212° F.                                        .sup.2 ASTM-D665A, 60° C. 24 hr.                                       .sup.3 ASTM-D2266-64, 1800 rpm 28 kg. room temp.                              .sup.4 ASTM-D2596, 1500 rpm. room temp.                                       .sup.5 ASTM-2272, 100 rpm. 90 psi 150° C.                              .sup.a The reaction product of C.sub.18 H.sub. 37 OPSCl.sub.2 and             piperazine, but with uncertain structure                                 

                                      TABLE 6                                     __________________________________________________________________________    Evaluation of Phenyl Bispiperazidophosphite                                                    Blend             4 Ball Mean Hertz    Rotary Bomb                            % wt in                                                                              Cu-strip   Navy Wear.sup.3                                                                      Load.sup.4                                                                           Weld Point.sup.4                                                                     Oxidation.sup.5       Compound         Base oil                                                                             Corrosion.sup.1                                                                     Rust.sup.2                                                                         micr/min                                                                             kg     kg     min                   __________________________________________________________________________     ##STR28##       2.0 SNO-20                                                                           1A    pass 1.8    54.7   158    70                    ZDT              2.0    --    --   0.2    62     251    120                                    SNO-20                                                       SNO-20           --     1A    severe                                                                             7.3    24     126    40                    __________________________________________________________________________     .sup.2 ASTM-D665A, 60° C., 24 hr.                                      .sup.3 ASTM-D2266-64, 1800 rpm. 28 kg. room temp.                             .sup.4 ASTM-D2596, 1500 rpm. room temp.                                       .sup.5 ASTM-2272, 100 rpm. 90 psi, 150° C.                        

The solubility in base oils at room temperature of phosphorothioictris-(N'-β-carbethoxyethylpiperazide) is 0.6% wt in SNO-20 and 0.3% wtin 145-PPT, allowing an evaluation as lube oil additive.

The compound has good antiwear properties and mild extreme pressureactivity, compared to ZDT a zinc dialkyl dithiophosphate.

Test data are given in Table 7 below:

                                      TABLE 7                                     __________________________________________________________________________               Phosphorothioic                                                               tris-(N'-β-carbethoxy                                                                    ZDT in SNO-20                                      Bench Test ethylpiperazide)                                                                         SNO-20                                                                             0.5 wt. %                                                                          1 wt. %                                       __________________________________________________________________________    Cu strip corrosion                                                            ASTM-D130; 3 hr;                                                                         1A         1A   --   1A                                            212° F.                                                                Rust ASTM-D665A                                                               60° C., 24 hr                                                                     severe     severe                                                                             --   moderate                                      4 ball Navy Wear                                                              ASTM-D2266-64                                                                 1800 rpm   0.5 micr/  7.3  --   0.3 micr/                                     28 kg, room temp                                                                         min        micr/min  min                                           Mean Hertz Load                                                               ASTM-D2596                                                                    1500 rpm, room temp                                                                      43.3 kg     24 kg                                                                              48 kg                                                                             54.9 kg                                       Weld Point                                                                    ASTM-D2596                                                                    1500 rpm, room temp                                                                      158 kg     126 kg                                                                             224 kg                                                                             200 kg                                        Rotary bomb oxi-                                                              dation     30 min     40 min                                                                             --   65 min                                        ASTM 2272, 100 rpm,                                                           90 psi, 150° C.                                                        __________________________________________________________________________

Although this invention has been illustrated by reference to specificembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made which clearly fall withinthe scope of this invention.

What I claim is:
 1. ##STR29##
 2. ##STR30##
 3. ##STR31##